Halogenated red dye and process of making same.



UNITED s'rATns PATEN OFFICE.-

GADIENT .ENGI, OF BASICL, SWITZERLAND, ASSIGN TO THE FIRM OF SOCIETY OF CHEMICAL INDUSTRY IN BASLE, OF BASEL, SI/VITZER- LAN D.

HALOGENATED RED DYE AND PROCESS OF MAKING SAME- Specification of Letters Patent.

Patented 'March 26, 1907.

Application filed January 9, 1907- Serial No. 351.442.

ist and doctor of philosophy, a citizen of the Swiss Republic, and a resident of Basel, Switzerland, have invented new and useful llalogenated Red Vat-Dyeing Dyestu'll's and a Process for the Manufacture of the Same, of

I which the following is a full, clear, and exact specification.

In the United States Letters Patent No. 831,844, dated Septen'ibern 25, 1906, I have described the manufacture of a red vat-dyeing dyestu'fl', by heating: salicylthioacetic acid I ()()ll (lnll,

S1 ll-:UOUI! (2) with an aromatic nitrohydrocarbon. Since I have found that dyestufl's more fast to Washing and dyeing yellmver red tints and constituting, consequently, more valuable products can be obtained if in the process of the said Letters Patent No. 831,844 the salicylthioacetic acid is replaced by its halogenated derivatives containing the halogene in the position para relatively to the carboxylic group'as, for instance, nietachlorsalicyltlnoacetic acidcoou (1' Gil-l3 -SOHQCOOI-I (2) c1 (4.) 0r lnetabromsalicylthioacetic acid JOOH (1) (ML SCIIZCOOHQ) lir /UOOH (1) cu-uscmcoon (2) c1 (4 are heated with fifty parts of nitrobenzene, during, three to five hours in a reflux apparatus, in an oil bath, at 225 to 228 centigrade, (temperature of the oil-bath.) the cooled mass of reaction the dyestuff is separated by filtration. It is Washed on the I ilter with alcohol and dried. This dyestufl" constitutes a reddish crystalline powder, which is very diflicultly soluble in the usual organic solvents, as alcohol, ether, and chloroform. Its solution in warm benzene shows a bluish-red coloration and a yellow-pale fluorescence. In boiling nitrobenzene it dissolves with a lively red coloration. Its solution in concentrated sulfuric acid has'a green coloration, and on addition of water to this solution the unchanged dyestuff separates in form of bright red flocks. In fuming sulfuric acid the new dyestufl' dissolves even in the cold with a red coloration'and with formation of a snlfonic acid. When made into a vat with the usual reducing agents, particularly with caustic-soda lye and. sodium-hydrosulfite, the dycstu'ff yields a bright goldyellow vat'from which the difl'erent textile fibers are dyed in clear red tints, which are much yellower and faster to Washin than those obtained with the dyestuff erived frogi the not halogenated salicylthioacetic aci If in the foregoing example the chlorsalicylthioacetic acid is replaced by the corresponding brom derivative, the resultingdycstufi' ofiers analogous properties.

That I claim is- 1. The described process for the manufacture of red vat-dyeing dyestuffs by heating the meta-halogenated salicylthioacetic acid coon (1)' OtHs (2) Halogen (4) with aromatic nitrohydrocarbons.

2. As a new article of manufacture, the herein-described yellowish red vat-dyeing dyestufl' constitutinga reddish crystalline From soluble in concentrated. sulfuric acid with a powder, very difllcultly soluble in alcohol, ether and chloroform, soluble in warm bonzene with a bluish red coloration and a, elloKvish-pale fluorescence, soluble in boiing In witness whereof I have' hereunto signed nitroben'zene with a. lively rod coloration;

my name, this 19th day of December, 1906, 10 in the presence of two subscribing witnesses.

GADIENT ENGL \Vitnesses GEO. GI FoRn,

green coloration and soluble 11 fuming sul- AMAND RITTER.

furic acid rerl coloration. 

